Oil Desalting Research Articles

Analysis of Hydrodynamics of Horizontal Electric Dehydrators for Determining Ways of Intensification of Electrical Crude Oil Desalting and Dehydration

Analysis of Hydrodynamics of Horizontal Electric Dehydrators for Determining Ways of Intensification of Electrical Crude Oil Desalting and Dehydration

Cellulose derivative polymers for demulsification of lagoon wastewater-in-crude oil systems: An efficient water reuse strategy

Removal of ions from produced crude oil necessitates desalting with water. During desalting it is essential to remove aqueous impurities from oil to avoid corrosion and fouling in upstream oil industry as well as catalyst deactivation in downstream processing. It is also important to simultaneously minimize the environmental impact of produced wastewater by cost-effective industrially feasible techniques. Since the ion content of wastewater discharge of oil desalter unit is far from saturation, its reuse for further desalting of crude oil is proposed in this study. Biocompatible carboxymethyl cellulose (Walocel), two methyl cellulose with different methyl and 2-hydroxypropyl derivative contents (Methocel K3 and Methocel E5), and cellulose acetate, are used to promote demulsification of well water- and lagoon wastewater-in-crude oil emulsion. Screening bottle tests revealed that Walocel and Methocel E5 are more suitable. Walocel and Methocel E5 at 3000 ppm could remove 97.6% and 91.7% of well water from oil at 80 °C. It was observed that presence of hydrocarbon impurities and previously added demulsifier in lagoon wastewater greatly enhances initial demulsification rate for Walocel and Methocel E5 up to 5.5 and 19.6 times, respectively. Walocel and Methocel E5 at a final concentration of 3000 ppm could remove 93.5 ± 3.6% and 95.8 ± 4.2% of lagoon wastewater within 60 min at 80 °C and finally remove all oil content of the emulsion. Superior performance of Methocel E5 in complete demulsification of lagoon wastewater-in-oil is attributed to abundance of hydrogen bond forming oxygen atoms in its cellulosic backbone as well as amphiphilic 2-hydroxypropyl and hydrophobic methyl side chains which constructively interact with water molecules and hydrocarbon impurities in the lagoon wastewater. The results of this study revealed that reuse of oily wastewater in crude oil desalting may be practical and such demulsification could be fast.

Evaluation of the Different Compatibility Indices to Model and Predict Oil Colloidal Stability and Its Relation to Crude Oil Desalting

Thirty crude oils, belonging to light, medium, heavy, and extra heavy, light sulfur, and high sulfur have been characterized and compatibility indices defined. Nine crude oil compatibility indices have been employed to evaluate the compatibility of crude blends from the thirty individual crude oils. Intercriteria analysis revealed the relations between the different compatibility indices, and the different petroleum properties. Tetra-plot was employed to model crude blend compatibility. The ratio of solubility blending number to insolubility number was found to best describe the desalting efficiency, and therefore could be considered as the compatible index that best models the crude oil blend compatibility. Density of crude oil and the n-heptane dilution test seem to be sufficient to model, and predict the compatibility of crude blends.

Optimum Temperature in the Electrostatic Desalting of Maya Crude Oil

The main variables that impact the crude oil desalting process were analyzed by developing mathematical models that rep- resent the variation of Maya crude oil density, conductivity and vis- cosity as functions of temperature. An increase in process tempera- ture has two opposite effects. First, a decrease in oil density and vis- cosity implies a significant increase in the settling rate of water droplets within the oil phase; which allow for a greater amount of oil to be processed. This increases the profit resulting from performing oil desalting. On the other hand, crude oil conductivity increases exponentially with temperature, which implies a higher rate of power consumption. A simulation model was developed to determine the optimum temperature at which a maximum economic benefit occurs. It was concluded that an optimum temperature occurs at 135 o C.

Comparative Analysis of Mixing Intensity and Losses Due to Hydraulic Resistance in Mixers of Electrical Desalting Plants

A comparative analysis of the intensity of mixing processes and losses due to hydraulic resistance in variously designed mixers used in electrical desalting plants of oil refineries was made. The effect of the working fluid feed rate was studied to analyze the flow structure in the working space of the apparatuses and to determine the hydrodynamic conditions that are favorable for execution of the flow mixing process and that excludes formation of stagnant areas in the equipment. The obtained results of numerical simulation of velocity and pressure fields can be used at the initial stage of design of new mixers (to justify choice of the shape, size of the working area, etc.) and to determine the optimum technological conditions of the operating apparatuses for crude oil desalting and dehydration (to reduce energy and fresh water consumption).

MODELING OF THE PROCESS OF POURING THE PRODUCT THROUGH THE RECEIVER-DISTRIBUTING DEVICE VST

Preserving quality and quantity of a product is an important task during the operation of tank farms. This requires maximum sealing of all processes of pouring, discharging and storing. Tanks have the largest share of evaporation losses throughout the course of the oil flow from fishing to refineries, at factories and petroleum product pipelines from factories to consumers. The process of storage of oil and petroleum products is combined with other technological operations (desalting of oil, heating, dehydration, mixing, etc.).
 One of the most important methods of saving fuel and energy resources, which occupy a leading place in the development of the economy, is the fight against oil products losses. The issue of product losses due to the lack of equipment and the durability of its use is important. One of them is a receiving and distributing device, which is installed in vertical steel tanks.
 To compare two of the most common variants of the execution of the disengagement body of the (ПРУ що це таке), a simulation of the process of pouring the product into the reservoir was performed using the Ansys 19.1 program. This made it possible visually to see how the receiving and distributing device works and what its efficiency can depend on. From the model of pressure distribution to the wall of the case (ПРУ) it is evident that when smoothly turning the housing, the pressure is distributed more evenly, due to which the load on the corner and the entrance to the receiver-distributing device in the wall of the tank will be less than when turning with the insert.
 In this article an analysis of the possibility of improving the outdated technologies and the use of the latest in the storage of petroleum products is given. The use of a receiving and dispensing device can significantly increase the inter-cleaning period during the operation of the reservoir, as well as reduce the amount of work when cleaning the reservoir. This will reduce the level of dead remains, improvement the service life of the lower belt and the bottoms of vertical steel tanks, by reducing the zone of corrosive activity of the bottom sediment.

Crude Oil Desalting Using Multi-Surfactant Based on a Best Dosage, Solvent and Mixing Ratio

Crude oil desalting is the first processing step in a refinery. The objectives of crude desalting are the removal of salts, solids, and the formation of water from unrefined crude oil before the crude is introduced in the crude distillation unit of the refinery. The experimental work is divided into three schemes covering the effect of surfactant dosage, test different types of surfactants, and the effect of salt content on desalting efficiency. The results show that the crude oil desalting efficiency, increased with increasing surfactant quantity. The results indicate that desalting efficiency has lowered with increasing the salt content in crude oil. Also, the results show that the best solvent was toluene, and the best mixing ratio of solvent was 10 Vol. %.

Influence of Turbulence on the Processes of Creation and Destruction of Water-Oil Emulsions During Crude Oil Desalting

It is shown that the additional turbulence of the flow in the processes of electric desalting of oil will substantially intensify existing technologies. Turbulence facilitates the mixing of the emulsion, the convergence of droplets and increases the probability of merging of droplets. The electric field contributes not only to the convergence of droplets, but also to the destruction of adsorption films around the drops. Therefore, combining the treatment of an emulsion in an electric field with a turbulent regime of its motion leads to a sharp improvement in the quality of oil demulsification. It is concluded that in order to find the optimal parameters for the operation of industrial devices, a theory is needed that, in addition to the droplet motion mechanism in turbulent vortices, also describes deformation of droplets, as well as the processes of destruction and the confluence of droplets. For studying the processes of changes in the topography of heterogeneous systems and the diagnosis of turbulent flows, the most promising is the numerical method for modeling the structure of flows.

Effect of Electric Field Nonuniformity on the Processes of Creation and Destruction of Water-Oil Emulsions During Crude Oil Desalting

The effect of electric field nonuniformity on the processes of creation and destruction of water-oil emulsions during crude oil desalting was investigated. It is shown that electrodemulsification of crude oil in a uniform electric field is ineffective. To increase the efficiency of electro-desalination, it is proposed to provide in the apparatus three contact stages with various hydrodynamics of the emulsion flow and electric field strength. It is suggested to place electrodes in the horizontal body of the apparatus. For this, one electrode is executed in the form of vertical injectors for “dry” and/or initial emulsion, and the second – in the form of a flat Venturi channel. Any productivity can be achieved by increasing the length of the apparatus, and electric field nonuniformity and strength adjustments make it possible to obtain three stages of separation of the emulsion.

Influence of Electric Field Strength on the Processes of Destruction and Creation of Water-Oil Emulsions During Crude Oil Desalting

It is shown that the use of an electric field significantly intensifies the process of destruction of water-oil emulsions, because for each droplet size there is a critical tension at which they begin to disperse. As the dispersal of the dispersed phase is coarsened, it is necessary to gradually reduce the magnitude of the electric field strength and reduce the flow rate of the emulsion. At the first stages of the destruction of an emulsion with high water content, it is advisable to conduct dehydration by other methods, and electrohydrodynamic treatment is used only in the subsequent stages. At different stages of electrohydrodynamic processing, depending on the degree of dispersion of the system, it is necessary to vary the distance between the electrodes and electric field intensity in the electrocoalescence zone. It was found that the most rational design of electrohydrodynamic coalescers and dispersers from the point of view of obtaining maximum efficiency at the optimal energy inputs are multi-stage apparatuses in which the water-oil emulsion sequentially passes stages with varying parameters of the electric field.

IMPROVING OF OIL DESALINATION QUALITY IN FIELDS DUE TO THE RATIONAL MOVEMENT AND INTERACTION ORGANIZATION OF THE MIXED OIL AND WATER FLOWS

The technological process of desalting in electro-desalination plants presupposes the presence of mixing devices located in front of the electric dehydrators, for mixing oil with washing water. Special requirements are imposed on washing water: the chloride content in water should not exceed 300 mg/l, sulfates and carbonates - 300 mg/l, hydrogen sulfide - 20 mg/l; the medium must be neutral or slightly alkaline. Mixing devices turbulize the mixed streams, wash water globules collide with globules of mineralized water present in the oil, break up and again collide, merging with some of them. In the coagulated globule of water, only a partial equalization of the salt concentra-tion occurs. Therefore, the degree of desalting is not equal to the degree of dehydration, the rinsing water must be supplied to the oil with a large excess. The total amount of washing water for the desalination system with Russian and foreign mixers ranges from 5 % to 20 % for processed oil. In the oil-water hydralic jet mixers (SGS N-V), a counter-directed movement of the puri-fied washing water in the form of a finely dispersed phase and oil is organized. Dispersity and speed of movement of wash water globules are set by the structural elements of the mixer and are determined by hydrostatic head and oil and water consumption. This paper explains the mechanism of effective desalting of oil in fields when mixed with water in a mixer SGS N-V, installed in a pipe in front of the electrohydrators in electro-desalination plants.

Crude Oil Desalting by Using Nanocarbon

In the process of crude oil desalination, the aim is to separate dispersed phase of brine from oil phase. The project aim is the use of carbon nano-adsorbent for remov-al of salt from crude oil that, unlike other methods of salt separation from crude oil currently used, is a simple, inexpensive method with good ability to remove salt from crude oil. In this study, first, four types of carbon adsorbent were used for removal of salt from crude oil using dispersion in solution method. Then, the adsorbents that had the best absorption were identified. In continuation, two nano-adsorbents were selected from nano-adsorbents and their effect on the absorption of salt from crude oil was investigated using filtration method. Finally, a survey was carried out on regeneration of multi-walled carbon nanotubes that had the ability to absorb more than 50% of salt from crude oil, which were then selected as the best nano-adsorbents.

DESIGN JUSTIFICATION OF THE MIXING DEVICE FOR EFFECTIVIZATION OF OIL DEHYDRATION AND DESALTING

The article shows the relevance and prospects of enhancing the effectiveness of oil dehydration and desalting by optimizing hydrodynamic regime. It identified the key processes in the equipment, affecting the efficiency of dehydration and desalting of oil, distribution of demulsifier and wash water in the treated stream of oil and the possibility of their optimization through the use of advanced equipment. Is a schematic design of the mixing device based on a new approach to the organization of the dispersion component introduced in separate streams generated with straightening canals. The provisions set out in the article are the basis for the further development of the modernized design of the mixer, and the calculation of the basic operating parameters.

Optimization of Operating Parameters of Oil Desalting in Southern Treatment Unit (HMD/Algeria)

Crude oil often contains fine saline water droplets, salt crystals, suspended solids and traces of metals. To meet business requirements, the salinity of the latter is limited to 40 mg/L and (BS&W) Basic Sediment and Water must to be lower than 1%. For this reason and to prevent corrosion, plugging, and fouling of equipment, electrical desalting plants are often installed in crude oil production units. This paper presents the results of a laboratory work conducted regarding the impact of important key parameters of oil desalting, namely: the rate of wash water, oil temperature, and injected chemical demulsifier amount in aim to achieve their optimum value and thus to reach the lowest oil salinity and (BS&W) without applying electrical field. Experiments conducted in South Crud Treatment Unit laboratory (UTBS/Hassi-Messaoud/Algeria), showed that the salts removal efficiency (SRE) increases with increasing the wash water rate, demulsifier amount and operating temperature. For 5% of wash water rate and 0.5% of demulsifier at 52°C, the (SRE) was 96.94%. Applying these parameters values to electrical desalting vessel with electrical field supply, would increase the (SRE) to a remarkable extent. The mean value recorded for (BS&W) during experiments was only 0.5%.

THE CALCULATION OF PARAMETERS OF THE MIXING APPARATUS WITH A VORTEX DEVICES BY METHODS OF MATHEMATICAL STATISTICS AND PATTERN IDENTIFICATION FOR THE QUALITY OIL DESALTING IN CDU

Oilfield water and oil form oil-water emulsion under existing methods of oil production. Oilfield water is heavily mineralized fluid with a high content of chlorides of sodium, magnesium, calcium, and sulfates and bicarbonates, mechanical impurities. The presence in the oil of these impurities have a negative impact on both the safe, efficient operation of equipment of oil refining installations and the ecological safety of the environment: 1) large water content rises excessively the pressure in the apparatus of distillation of crude oil; 2) salt in the form of sedimentation in pipes and heat exchangers lead to corrosive rustiness; 3) reduce the quality of secondary products of oil refining - fuel-oil residue and tar. Technological processes of dehydration and desalting is used to remove oilfield water from oil-water emulsion. Primary dehydration of oil-water emulsion is produced in the fields by settling with the addition of demulsifiers. The residual content of salts and water in oil emulsion is removed due to the desalination process. The technological process of oil desalting involves mixing the oil, water and demulsifier. Desalination process efficiency depends strongly on the degree of mixing oil, water and demulsifier. It is proposed to use mixers with vortex devices for intensive mixing. Theoretical and experimental studies aimed at improving the processes of oil treatment for refining have been done. A stochastic model of the work of mixers with vortex devices has been constructed. The criteria characterizing the work of the vortex devices for mixing of oil, water and demulsifier have been defined. Regularities of the influence of the found parameters on the quality of desalting have been identified.

A Novel Modeling and Experimental Study of Crude Oil Desalting using Microwave

In this study a novel experimental procedure for the crude oil desalting process using microwave field is designed and a mathematical model is developed to predict the global coalescence rates and the evolution of the saltwater separation under the influence of the microwave field. The results of the model are validated by experimental data and a good qualitative agreement between the model predictions and experimental results is observed. Using the model, the effects of microwave residence time, volumetric energy density, and amount of fresh water injection have been studied. The results show that the novel microwave mathematical model can be used in designing the microwave oil desalters.

Influence of key parameters on crude oil desalting: An experimental and theoretical study

Desalting plants are often installed in crude oil production units in order to remove water-soluble salts from an oil stream. Experiments in both the laboratory and field have shown the desalting process parameters to be very complicated.This research reflects the results of a study conducted regarding the impact of operational desalting parameters, including the effects of temperature, injected chemicals and the pH of the crude oil associated water, on an electrostatic desalter on one of the oil platforms owned by the Iranian Oil Offshore Company in the Persian Gulf. The temperature range applied was between 98 to 133°C, at which the effects on water and oil density as well as salt efficiency and Basic Sediment & Water (BS&W) were studied. The results demonstrate that for high desalting efficiency a temperature between 115 to 120°C is required. In order to determine which demulsifier provides optimum conditions, the functions of various demulsifiers (noted as C, D, E, F, G and H) on a water–oil emulsion were tested in the laboratory, with C and F providing the optimum output. Accordingly, the field test utilized these two selected demulsifiers. Injection of 50 to 100ppm demulsifier produced optimum separation of 88% for BS&W and approximately 99% for salt. Furthermore, the effect of pH of the crude oil in the water–oil emulsion samples was tested in the laboratory and a suitable range determined to be between 9 and 12.Theoretical calculations utilizing fuzzy logic were performed. These showed satisfactory agreement between the experimental and theoretical results obtained.

Chlorinated solvents in a petrochemical wastewater treatment plant: An assessment of their removal using self-organising maps

The self-organising map approach was used to assess the efficiency of chlorinated solvent removal from petrochemical wastewater in a refinery wastewater treatment plant. Chlorinated solvents and inorganic anions (11 variables) were determined in 72 wastewater samples, collected from three different purification streams. The classification of variables identified technical solvents, brine from oil desalting and runoff sulphates as pollution sources in the refinery, affecting the quality of wastewater treatment plant influent. The classification of samples revealed the formation of five clusters: the first three clusters contained samples collected from the drainage water, process water and oiled rainwater treatment streams. The fourth cluster consisted mainly of samples collected after biological treatment, and the fifth one of samples collected after an unusual event. SOM analysis showed that the biological treatment step significantly reduced concentrations of chlorinated solvents in wastewater.

Pretreatment of Crude Oil by Ultrasonic-electric United Desalting and Dewatering

A technology of ultrasonic-electric united desalting and dewatering of crude oil is studied. The ultrasonic setup is designed to form a standing-wave field, which is more efficient for agglomeration of water particles. The desalting and dewatering results of the ultrasonic-electric united process are compared with those of the electric process. For high salt-contenting crude oil (40-70 mg·L −1), the salt content is still above 10.0 mg·L −1 after crude oil has been treated by two-stage electric desalting process in refinery, which cannot meet the need of refinery. Ultrasonic-electric united process is a novel technology for treating the high salt-contenting oil. On the optimal operating conditions of the ultrasonic-electric united process, the salt content of crude oil can be reduced from 67.5 mg·L −1 to 3.97 mg·L −1 by one-stage ultrasonic-electric united process, and the water content falls below 0.3% (by volume). The results show that the ultrasonic-electric united process is more effective than the electric process in high salt-contenting oil desalting. This technology should be useful in the refinery process.

Continuous De-emulsification of Crude Oil Using Packed Column Under Various Conditions

This research dealt with desalting of East Baghdad crude oil using pellets of either anionic, PVC, quartz, PE, PP ornonionic at different temperature ranging from 30 to 80 °C, pH from 6 to 8, time from 2 to 20 minutes, volume percentwashing water from 5 to 25% and fluid velocity from 0.5 to 0.8 m/s under voltage from 2 to 6 kV and / or using additivessuch as alkyl benzene sulphonate or sodium stearate. The optimum conditions and materials were reported to removemost of water from East Baghdad wet crude oil.